DPDK lacp bonding - xmit hash

DPDK lacp bonding - xmit hash

[Vincent]

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What determines what xmit_hash_policy DPDK will use for LACP bonded links?
Does it not respect the value specified by
/sys/class/net/<INTERFACE>/bonding/xmit_hash_policy?

Based on testing, it seems like layer2, or layer3+4 hashing is being done,
but the behavior is random, and seems to not necessarily reflect the
current value specified by
/sys/class/net/<INTERFACE>/bonding/xmit_hash_policy.

Thank you,

Vincent

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Re: DPDK lacp bonding - xmit hash

[Stephen Hemminger]

On Wed, 18 Sep 2024 18:20:53 -0400
Vincent <techburgher@gmail.com> wrote:

> What determines what xmit_hash_policy DPDK will use for LACP bonded links?
> Does it not respect the value specified by
> /sys/class/net/<INTERFACE>/bonding/xmit_hash_policy?
> 
> Based on testing, it seems like layer2, or layer3+4 hashing is being done,
> but the behavior is random, and seems to not necessarily reflect the
> current value specified by
> /sys/class/net/<INTERFACE>/bonding/xmit_hash_policy.
> 
> Thank you,
> 
> Vincent

DPDK doesn't use the Linux kernel network interfaces.
The DPDK PMD is a completely separate user mode driver.

https://doc.dpdk.org/guides/prog_guide/link_bonding_poll_mode_drv_lib.html

The similar function DPDK bond PMD is the Balance XOR (Mode 2).
The configuration of the hash type is done via:
	rte_eth_bond_xmit_policy_set()